1. Field of the Invention
The present invention relates to a projection type scanning image display system, which operates mirrors for reflecting input light and, thus, modulates the path of the reflected light in a space, thus forming an image.
2. Description of the Related Art
A raster scanning display system provides a means for scanning a beam, which is emitted from a light source, onto a predetermined one-dimensional (linear) or two-dimensional (planar) region, thus representing information, such as an image. Furthermore, the raster scanning display system integrated with optical sensors, such as photodiodes or photodetectors, can be applied to scanners that scan and read information formed on a one-dimensional or two-dimensional region.
A scanning micro mirror according to the present invention can be applied to laser printers, confocal microscopes, barcode scanners, scanning displays, various sensors and the like, which scan a beam, which is emitted from a light source, onto a predetermined one-dimensional (linear) or two-dimensional (planar) region and displays information, such as an image, or read data, such as locations or an image. Furthermore, the scanning micro mirror according to the present invention can be applied to optical switching devices that require the static directional modulation of reflected light, in addition to the scanning devices.
Recently, with the development of optical device technology, various technologies that use light for stages for inputting and outputting various information and as a medium of information transfer are being developed. A method of scanning and utilizing a beam emitted from a light source is also one of the technologies, and typical examples of the method include a barcode scanner and a basic level of a scanning laser display. Such beam scanning technology demands a variety of scanning speeds and ranges depending on applications, and a method of using a galvanic mirror or a rotation-type polygon mirror is mainly used in existing beam scanning technology. The galvanic mirror is appropriate for applications that demand scanning speeds of several tens of hertz (Hz), and the polygon mirror can implement scanning speeds of several kilohertz (kHz).
Recently, with the development of various technologies, efforts are continuously made to apply the beam scanning technology to new devices, or to further improve performance in existing applications that adopt the beam scanning technology. A high-resolution projection display system using laser scanning, a head-mount type display, and a laser printer are good examples. The systems, which require high-quality beam scanning, generally demand scanners that are capable of implementing fast scanning speed and large angle displacement. Further, the method of using a conventional polygon mirror is embodied such that a polygon mirror is mounted on a high-speed rotational motor. Accordingly, the method has a limitation in increasing scanning speed, and is disadvantageous in that it is difficult to decrease the overall size of a system and the consumption of power. Furthermore, the noise generated by a motor must be reduced, and it is difficult to reduce costs due to the complicated structure.
FIG. 1 is a perspective view showing a conventional scanner using a polygon mirror and a galvanic mirror.
A conventional scanner includes a light source 1, an optical system 2, a polygon mirror 3, and a motor 4.
Referring to FIG. 1, input light 11, which is emitted from the light source 1, passes through the optical system 2 composed of various lenses, and is reflected by the polygon mirror 3. Accordingly, by rotating the polygon mirror 3 using the motor 4 located below the polygon mirror 3, reflected light 14 can be scanned in a direction identical to the rotational direction 12 of the polygon mirror 3. Although the scanner using the polygon mirror can implement relatively fast scanning, the scanner has limitation in application to high-resolution displays.